title: Terahertz near-field microscopy of complementary planar metamaterials: Babinet's principle.
abstract: Using terahertz near-field imaging we experimentally investigate the resonant electromagnetic field distributions behind a split-ring resonator and its complementary structure with sub-wavelength spatial resolution. For the out-of-plane components we experimentally verify complementarity of electric and magnetic fields as predicted by Babinet's principle. This duality of near-fields can be used to indirectly map resonant magnetic fields close to metallic microstructures by measuring the electric fields close to their complementary analogues which is particularly useful since magnetic near-fields are still extremely difficult to access in the THz regime. We find excellent agreement between the results from theory, simulation and two different experimental near-field techniques.
authors.affiliation: Institute of Applied Physics, University of Bern, Sidlerstr 5, CH-3012 Bern, Switzerland. andreas.bitzer@gmail.com
authors.forename: Andreas
authors.initials: A
authors.lastname: Bitzer
authors.forename: Alex
authors.initials: A
authors.lastname: Ortner
authors.forename: Hannes
authors.initials: H
authors.lastname: Merbold
authors.forename: Thomas
authors.initials: T
authors.lastname: Feurer
authors.forename: Markus
authors.initials: M
authors.lastname: Walther
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008420:Manufactured Materials; D008422:Materials Testing / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D008962:Models, Theoretical; D055053:Terahertz Radiation